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191.
Isao Kaneko Makoto Iyama-Kadono Kana Togashi-Nishigata Isamu Yamaguchi Tohru Teraoka Tsutomu Arie 《Mycoscience》2013,54(2):148-157
Heterotrimeric GTP-binding proteins (G proteins) and mitogen-activated protein kinase (MAPK) cascades involve vegetative hyphal growth, development of infection-related structure, colonization in host plant and female fertility in phytopathogenic ascomycete fungi. In this study, a heterotrimeric G protein β subunit (Gβ), GPB1, and MAPK, MPK1, were characterized from Fusarium sacchari (= Gibberella sacchari; mating population B of the G. fujikuroi-species complex). GPB1 and MPK1 showed high homology to known Gβ and Fus3/Kss1 MAP kinases of other filamentous ascomycetes, respectively. Disruption (Δ) of gpb1 suppressed hyphal branching and accelerated aerial hyphae formation in F. sacchari. Oppositely, disruption of mpk1 caused delayed aerial hyphae formation. These indicated that GPB1 regulates vegetative hyphal growth negatively, and MPK1 does positively in F. sacchari. Both Δgpb1 and Δmpk1 showed female sterility. Level of intracellular cAMP in Δgpb1 was lower than wild type. Exogenous cyclic AMP (cAMP) partially restored enhanced aerial hyphae formation. These suggested that abnormal hyphal growth was caused by depletion of intracellular cAMP in Δgpb1. cAMP has been reported to suppress development of perithecia in crossing between wild type strains. Thus, precise regulation of intracellular cAMP level via Gβ/MAPK is essential for normal hyphal growth and fertility. 相似文献
192.
Saki Nagano-Koyashiki Makoto Matsubayashi Isao Kimata Masaru Furuya Hiroyuki Tani Kazumi Sasai 《Parasitology international》2013,62(2):109-111
Cryptosporidium andersoni is a protozoan parasite found in many countries that invades the stomachs of primarily adult cattle. Unlike the isolates of C. andersoni in cattle from other countries, C. andersoni isolates from Japanese cattle can infect mice and were identified as a novel type and later defined as C. andersoni Kawatabi type. The biological characteristics of C. andersoni Kawatabi type have not yet been well documented. In the present study, we assess the infectivity of this type isolate in mice with different immune competence status and age. We found that inoculation of more than 1 × 104 oocysts is needed to establish infection in mature mice irrespective of immune status. All of the infected immunocompetent mice recovered after a patent period of approximately 20 days. In immunodeficient mice, the pre-patent period was prolonged compared with that of 1 × 106 oocysts, but the pattern and the maximum shedding measured by the number of oocysts per day were almost identical. In neonatal immunocompetent and immunodeficient mice, inoculation with 1 × 104 to 105 oocysts was also needed to establish infection. Our results indicate that there is a threshold of oocysts needed to establish patent infection in the acidic conditions of the stomach. 相似文献
193.
Jun Kojima Jun Araya Hiromichi Hara Saburo Ito Naoki Takasaka Kenji Kobayashi Satoko Fujii Chikako Tsurushige Takanori Numata Takeo Ishikawa Kenichiro Shimizu Makoto Kawaishi Keisuke Saito Noriki Kamiya Jun Hirano Makoto Odaka Toshiaki Morikawa Hiroshi Hano Satoko Arai Toru Miyazaki Yumi Kaneko Katsutoshi Nakayama Kazuyoshi Kuwano 《Respiratory research》2013,14(1):30
Background
Marked accumulation of alveolar macrophages (AM) conferred by apoptosis resistance has been implicated in pathogenesis of chronic obstructive pulmonary disease (COPD). Apoptosis inhibitor of macrophage (AIM), has been shown to be produced by mature tissue macrophages and AIM demonstrates anti-apoptotic property against multiple apoptosis-inducing stimuli. Accordingly, we attempt to determine if AIM is expressed in AM and whether AIM is involved in the regulation of apoptosis in the setting of cigarette smoke extract (CSE) exposure.Methods
Immunohistochemical evaluations of AIM were performed. Immunostaining was assessed by counting total and positively staining AM numbers in each case (n = 5 in control, n = 5 in non-COPD smoker, n = 5 in COPD). AM were isolated from bronchoalveolar lavage fluid (BALF). The changes of AIM expression levels in response to CSE exposure in AM were evaluated. Knock-down of anti-apoptotic Bcl-xL was mediated by siRNA transfection. U937 monocyte-macrophage cell line was used to explore the anti-apoptotic properties of AIM.Results
The numbers of AM and AIM-positive AM were significantly increased in COPD lungs. AIM expression was demonstrated at both mRNA and protein levels in isolated AM, which was enhanced in response to CSE exposure. AIM significantly increased Bcl-xL expression levels in AM and Bcl-xL was involved in a part of anti-apoptotic mechanisms of AIM in U937 cells in the setting of CSE exposure.Conclusions
These results suggest that AIM expression in association with cigarette smoking may be involved in accumulation of AM in COPD. 相似文献194.
195.
Chloe I. Bloom Christine M. Graham Matthew P. R. Berry Fotini Rozakeas Paul S. Redford Yuanyuan Wang Zhaohui Xu Katalin A. Wilkinson Robert J. Wilkinson Yvonne Kendrick Gilles Devouassoux Tristan Ferry Makoto Miyara Diane Bouvry Valeyre Dominique Guy Gorochov Derek Blankenship Mitra Saadatian Phillip Vanhems Huw Beynon Rama Vancheeswaran Melissa Wickremasinghe Damien Chaussabel Jacques Banchereau Virginia Pascual Ling-pei Ho Marc Lipman Anne O’Garra 《PloS one》2013,8(8)
196.
Tae Mogami Naho Yokota Mikiko Asai-Sato Roppei Yamada Shiro Koizume Yuji Sakuma Mitsuyo Yoshihara Yoshiyasu Nakamura Yasuo Takano Fumiki Hirahara Yohei Miyagi Etsuko Miyagi 《PloS one》2013,8(11)
Ovarian clear cell adenocarcinoma (CCC) is the second most common subtype of ovarian cancer after high-grade serous adenocarcinomas. CCC tends to develop resistance to the standard platinum-based chemotherapy, and has a poor prognosis when diagnosed in advanced stages. The ANXA4 gene, along with its product, a Ca++-binding annexin A4 (ANXA4) protein, has been identified as the CCC signature gene. We reported two subtypes of ANXA4 with different isoelectric points (IEPs) that are upregulated in CCC cell lines. Although several in vitro investigations have shown ANXA4 to be involved in cancer cell proliferation, chemoresistance, and migration, these studies were generally based on its overexpression in cells other than CCC. To elucidate the function of the ANXA4 in CCC cells, we established CCC cell lines whose ANXA4 expressions are stably knocked down. Two parental cells were used: OVTOKO contains almost exclusively an acidic subtype of ANXA4, and OVISE contains predominantly a basic subtype but also a detectable acidic subtype. ANXA4 knockdown (KO) resulted in significant growth retardation and greater sensitivity to carboplatin in OVTOKO cells. ANXA4-KO caused significant loss of migration and invasion capability in OVISE cells, but this effect was not seen in OVTOKO cells. We failed to find the cause of the different IEPs of ANXA4, but confirmed that the two subtypes are found in clinical CCC samples in ratios that vary by patient. Further investigation to clarify the mechanism that produces the subtypes is needed to clarify the function of ANXA4 in CCC, and might allow stratification and improved treatment strategies for patients with CCC. 相似文献
197.
Hiroto Terasaki Satoru Kase Makoto Shirasawa Hiroki Otsuka Toshio Hisatomi Shozo Sonoda Susumu Ishida Tatsuro Ishibashi Taiji Sakamoto 《PloS one》2013,8(7)
Asymmetrical secretion of vascular endothelial growth factor (VEGF) by retinal pigment epithelial (RPE) cells in situ is critical for maintaining the homeostasis of the retina and choroid. VEGF is also involved in the development and progression of age-related macular degeneration (AMD). We studied the effect of tumor necrosis factor-α (TNF-α) on the secretion of VEGF in polarized and non-polarized RPE cells (P-RPE cells and N-RPE cells, respectively) in culture and in situ in rats. A subretinal injection of TNF-α caused a decrease in VEGF expression and choroidal atrophy. Porcine RPE cells were seeded on Transwell™ filters, and their maturation and polarization were confirmed by the asymmetrical VEGF secretion and trans electrical resistance. Exposure to TNF-α decreased the VEGF secretion in P-RPE cells but increased it in N-RPE cells in culture. TNF-α inactivated JNK in P-RPE cells but activated it in N-RPE cells, and TNF-α activated NF-κB in P-RPE cells but not in N-RPE cells. Inhibition of NF-κB activated JNK in both types of RPE cells indicating crosstalk between JNK and NF-κB. TNF-α induced the inhibitory effects of NF-κB on JNK in P-RPE cells because NF-κB is continuously inactivated. In N-RPE cells, however, it was not evident because NF-κB was already activated. The basic activation pattern of JNK and NF-κB and their crosstalk led to opposing responses of RPE cells to TNF-α. These results suggest that VEGF secretion under inflammatory conditions depends on cellular polarization, and the TNF-α-induced VEGF down-regulation may result in choroidal atrophy in polarized physiological RPE cells. TNF-α-induced VEGF up-regulation may cause neovascularization by non-polarized or non-physiological RPE cells. 相似文献
198.
Many insects exhibit excellent capability of visual learning, but the molecular and neural mechanisms are poorly understood. This is in contrast to accumulation of information on molecular and neural mechanisms of olfactory learning in insects. In olfactory learning in insects, it has been shown that cyclic AMP (cAMP) signaling critically participates in the formation of protein synthesis-dependent long-term memory (LTM) and, in some insects, nitric oxide (NO)-cyclic GMP (cGMP) signaling also plays roles in LTM formation. In this study, we examined the possible contribution of NO-cGMP signaling and cAMP signaling to LTM formation in visual pattern learning in crickets. Crickets that had been subjected to 8-trial conditioning to associate a visual pattern with water reward exhibited memory retention 1 day after conditioning, whereas those subjected to 4-trial conditioning exhibited 30-min memory retention but not 1-day retention. Injection of cycloheximide, a protein synthesis inhibitor, into the hemolymph prior to 8-trial conditioning blocked formation of 1-day memory, whereas it had no effect on 30-min memory formation, indicating that 1-day memory can be characterized as protein synthesis-dependent long-term memory (LTM). Injection of an inhibitor of the enzyme producing an NO or cAMP prior to 8-trial visual conditioning blocked LTM formation, whereas it had no effect on 30-min memory formation. Moreover, injection of an NO donor, cGMP analogue or cAMP analogue prior to 4-trial conditioning induced LTM. Induction of LTM by an NO donor was blocked by DDA, an inhibitor of adenylyl cyclase, an enzyme producing cAMP, but LTM induction by a cAMP analogue was not impaired by L-NAME, an inhibitor of NO synthase. The results indicate that cAMP signaling is downstream of NO signaling for visual LTM formation. We conclude that visual learning and olfactory learning share common biochemical cascades for LTM formation. 相似文献
199.
Kenichi Tanaka Masaaki Nakayama Makoto Kanno Hiroshi Kimura Kimio Watanabe Yoshihiro Tani Yuki Kusano Hodaka Suzuki Yoshimitsu Hayashi Koichi Asahi Keiji Sato Toshio Miyata Tsuyoshi Watanabe 《PloS one》2013,8(12)
Background
Advanced glycation end product (AGE) accumulation is thought to be a measure of cumulative metabolic stress that has been reported to independently predict cardiovascular disease in diabetes and renal failure. The aim of this study was to evaluate the association between AGE accumulation, measured as skin autofluorescence, and the progression of renal disease in pre-dialysis patients with chronic kidney disease (CKD).Methods
Skin autofluorescence was measured noninvasively with an autofluorescence reader at baseline in 449 pre-dialysis patients with CKD. The primary end point was defined as a doubling of serum creatinine and/or need for dialysis.Results
Thirty-three patients were lost to follow-up. Forty six patients reached the primary end point during the follow-up period (Median 39 months). Kaplan-Meier analysis showed a significantly higher risk of development of the primary end points in patients with skin autofluorescence levels above the optimal cut-off level of 2.31 arbitrary units, derived by receiver operator curve analysis. Cox regression analysis revealed that skin autofluorescence was an independent predictor of the primary end point, even after adjustment for age, gender, smoking history, diabetes, estimated glomerular filtration rate and proteinuria (adjusted hazard ratio 2.58, P = 0.004).Conclusions
Tissue accumulation of AGEs, measured as skin autofluorescence, is a strong and independent predictor of progression of CKD. Skin autofluorescence may be useful for risk stratification in this group of patients; further studies should clarify whether AGE accumulation could be one of the therapeutic targets to improve the prognosis of CKD. 相似文献200.